Beefs up regular expressions in OSSEC config tests
Beefs up regular expressions in OSSEC config tests

The `File.contains()` matcher provided by Testinfra uses vanilla grep,
not PCRE. Even when properly escaping regex special characters prior to
running the .contains() matcher, certain characters such as `\s` or `+`
will always cause the match to fail. Falling back to Python regex fixes.

conorsch/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,ageis/securedrop,garrettr/securedrop,heartsucker/securedrop,heartsucker/securedrop,micahflee/securedrop,ehartsuyker/securedrop,ageis/securedrop,garrettr/securedrop,garrettr/securedrop,conorsch/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,conorsch/securedrop,garrettr/securedrop,ageis/securedrop,ageis/securedrop,micahflee/securedrop,micahflee/securedrop,micahflee/securedrop,conorsch/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,heartsucker/securedrop